MA abusing participants will undergo a 1-day outpatient screening and if it is safe for the participants to proceed with the study they will participate in two inpatient components of the study that will occur in the University of California Los Angeles (UCLA) General Clinical Research Center (GCRC). The first inpatient stay will be 15 days, and the second will be a 9 days stay that includes drug administration and assessments. There will be at least a two week interval between inpatient components. During the inpatient components participants will receive alternating study drugs; atomoxetine or placebo and four sessions of IV MA administration or saline.